The figure eight knot is one of the easiest fishing knots to tie and can be used for terminal tackle or as a very good stopper knot. It is generally used at night and in low light conditions because it is very easy to tie. It is sufficiently strong for some situations, but is certainly one of the weaker connection knots used today. A popular way to strengthen the knot is to double the line to tie this knot. However, this knot is still not recommended for tackling big fish.
This is also a popular rock climbing/boating knot that provides a strong connection and can be tied in a matter of seconds.
How to tie a figure eight knot